[FFmpeg-devel] [PATCH 5/6] avcodec/cfhd: Move peak_table() and difference_coding() calls after the existing coefficient count check

Michael Niedermayer michael at niedermayer.cc
Mon Aug 13 03:24:22 EEST 2018


Fixes: out of array access
Fixes: 9509/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_CFHD_fuzzer-5283250636324864
Fixes: 9572/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_CFHD_fuzzer-4920757409808384
Fixes: 9596/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_CFHD_fuzzer-5114917580439552
Fixes: 9640/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_CFHD_fuzzer-6247840698335232
Fixes: 9659/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_CFHD_fuzzer-6079554987753472

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavcodec/cfhd.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/libavcodec/cfhd.c b/libavcodec/cfhd.c
index 76838f0869..1959762f0e 100644
--- a/libavcodec/cfhd.c
+++ b/libavcodec/cfhd.c
@@ -668,11 +668,6 @@ static int cfhd_decode(AVCodecContext *avctx, void *data, int *got_frame,
                         for (i = 0; i < run; i++)
                             *coeff_data++ = coeff;
                     }
-                    if (s->peak.level)
-                        peak_table(coeff_data - expected, &s->peak, expected);
-                    if (s->difference_coding)
-                        difference_coding(s->plane[s->channel_num].subband[s->subband_num_actual], highpass_width, highpass_height);
-
                 } else {
                     while (1) {
                         UPDATE_CACHE(re, &s->gb);
@@ -692,11 +687,6 @@ static int cfhd_decode(AVCodecContext *avctx, void *data, int *got_frame,
                         for (i = 0; i < run; i++)
                             *coeff_data++ = coeff;
                     }
-                    if (s->peak.level)
-                        peak_table(coeff_data - expected, &s->peak, expected);
-                    if (s->difference_coding)
-                        difference_coding(s->plane[s->channel_num].subband[s->subband_num_actual], highpass_width, highpass_height);
-
                 }
                 CLOSE_READER(re, &s->gb);
             }
@@ -706,6 +696,10 @@ static int cfhd_decode(AVCodecContext *avctx, void *data, int *got_frame,
                 ret = AVERROR(EINVAL);
                 goto end;
             }
+            if (s->peak.level)
+                peak_table(coeff_data - expected, &s->peak, expected);
+            if (s->difference_coding)
+                difference_coding(s->plane[s->channel_num].subband[s->subband_num_actual], highpass_width, highpass_height);
 
             bytes = FFALIGN(AV_CEIL_RSHIFT(get_bits_count(&s->gb), 3), 4);
             if (bytes > bytestream2_get_bytes_left(&gb)) {
-- 
2.18.0



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